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I just hit the 13k mile mark and here is my new report. I think this pretty much confirms that BMW was using a low-zinc break-in oil. What does silicon in the oil have to do with an air filter? I love this car and want to keep it forever. As a result I think I am going to keep with their recommended oil change interval.

Thoughts?

Notes from the report:

Quote:

This oil was in place longer than the first sample, but wear improved pretty dramatically. This is a good sign that the engine is making its way through the wear-in process. Silicon is also washing out of the system, so we think the air filter is getting the job done. Low insolubles points to good oil filtration. Iron and copper will probably look even better next time. The TBN was a decent 2.6 with anything less than 1.0 being to low for extend use. No fuel or other harmful contaminants were present. Stay around 7,000 miles for now until iron drops a little more. Nice.

Question: What brand of oil did you use for this sample, and what did you re-fill with?

I got the oil changed at the dealer, both times. At around 10k miles I was a quart low, so I went to the dealer for a top off. Not so funny story, dude tried to top off with oil for a gasoline engine. "I didn't know they made diesel sedans". Good thing I checked.

Your first change was 5470 miles, correct ekay? My own car is just a little below that point now. I was considering doing a "customer pay" change, but since Blackstone confirmed the initial oil is some kind of special "break in" (or otherwise kinda exotic) maybe I might just wait until the one year point comes up and have BMW just do the complimentary "one year no matter how many miles" change...in other words, leave the first oil in for the full interval/or to one year point.

Please tell me what the letters "TBN" stand for?

Interesting how Blackstone commented that your initial oil "had a lot less zinc in it than usual." So yes it does appear to be a special oil. By the way, I have the exact same year/model 335 as the OP. Pretty good chance my sump has the same (initial-first) oil as he, I'd surmise.

Thanks again for the info!

rr-der

PS-- Yes, I have also needed a quart of "top off" oil to keep the level at the
top of the dipstick-- and used the specified Castrol CF (diesel approved) product.
That's what will go in at the first change, too.

Last edited by railroader; 08-09-2010 at 02:35 PM.
Reason: further info~~

Interestingly they (Blackstone) also does a TAN (Total Acid Number) test but they don't do it for vehicles. I wonder if you can special order that?

The general rule of thumb is that the oil is ready to be changed when TBN (moves downward) meets TAN (moves upward). There's a UOA out there on a X5d which had factory fill analyzed at normal OCI (ie, ~11k miles) and the TAN reading was @ around 4 while the TBN was @ around 1.

Interestingly they (Blackstone) also does a TAN (Total Acid Number) test but they don't do it for vehicles. I wonder if you can special order that?

The general rule of thumb is that the oil is ready to be changed when TBN (moves downward) meets TAN (moves upward). There's a UOA out there on a X5d which had factory fill analyzed at normal OCI (ie, ~11k miles) and the TAN reading was @ around 4 while the TBN was @ around 1.

I changed out my factory fill at 6,500 miles.

My $.02

Silicon can also be present in the oil's additive package when new.

Zinc is also present as it helps the oil hold up to higher pressure, i.e. between moving parts such as bearings and crankshafts.

TBN should be a non-issue since you are running on ULSD. TBN is the additive used to help neutralize the acid forming products of combustion that blow by the piston rings.

In large marine diesels burning HFO, sometimes with Sulphur as high as 3% or even higher, TBN is raised to up to 55. As time goes the additive is depleted and TBN will drop until it reaches an equilibrium point or plateau. This plateau should be reached before 50%of the additive is depleted, or say a TBN of 27.5. If it drops below 50% you need to refresh or change the oil with the higher TBN.

When a diesel engine is burning ULSD, TBN is no longer an issue, there is no more acid forming sulphur to neutralize.

Zinc is also present as it helps the oil hold up to higher pressure, i.e. between moving parts such as bearings and crankshafts.

TBN should be a non-issue since you are running on ULSD. TBN is the additive used to help neutralize the acid forming products of combustion that blow by the piston rings.

In large marine diesels burning HFO, sometimes with Sulphur as high as 3% or even higher, TBN is raised to up to 55. As time goes the additive is depleted and TBN will drop until it reaches an equilibrium point or plateau. This plateau should be reached before 50%of the additive is depleted, or say a TBN of 27.5. If it drops below 50% you need to refresh or change the oil with the higher TBN.

When a diesel engine is burning ULSD, TBN is no longer an issue, there is no more acid forming sulphur to neutralize.

Zinc is also present as it helps the oil hold up to higher pressure, i.e. between moving parts such as bearings and crankshafts.

Interesting.

I though the Zinc was for protection when the localized oil pressure was momentarily too low, allowing metal-to-metal contact, e.g., lots of zinc in gear oils because of lower oil pressure, not higher oil pressure, but of little importance in bearings and crankshafts since there is no metal-to-metal contact under operating conditions. From what I have read over the years, zinc phosphate had no effect on the plain bearings used for crankshafts, but has more to do with piston ring and cylinder wear at the top and bottom of the piston stroke when the rings reverse direction and momentarily reach zero velocity, unlike a plain bearing.

Zinc is also present as it helps the oil hold up to higher pressure, i.e. between moving parts such as bearings and crankshafts.

TBN should be a non-issue since you are running on ULSD. TBN is the additive used to help neutralize the acid forming products of combustion that blow by the piston rings.

In large marine diesels burning HFO, sometimes with Sulphur as high as 3% or even higher, TBN is raised to up to 55. As time goes the additive is depleted and TBN will drop until it reaches an equilibrium point or plateau. This plateau should be reached before 50%of the additive is depleted, or say a TBN of 27.5. If it drops below 50% you need to refresh or change the oil with the higher TBN.

When a diesel engine is burning ULSD, TBN is no longer an issue, there is no more acid forming sulphur to neutralize.

15ppm vs 30,000ppm Sulphur.

TAN is what you should be concerend with I think.

Meh. Even with ULSD, there is some production of acids. I did an engine oil and filter replacement at 1200 miles, and the TBN was at 6.8. The next oil analysis showed a TBN result of 4.8. If there was no production of acids, TBN should not have dropped 2 whole points.

TAN measures sample acidity. TAN is usually measured when analyzing transmission or differential oil due to the general absence of acid reduction additives in the transmission/differential oil.

The interesting measures that no one has commented on yet are the OP's sample viscosity results. Those were within the range for each test, which is good.

Based upon only my own personal limited experience with the 335d, it has consumed Zero lube oil. This means no make up has been added, so no refreshing. Which in itself is an amazing feat for today's modern diesel engines. I recall having to add a quart of oil about every 1-2k miles, betwen leaks and combustion!

So, that means there is only dilution and pollution of the oil, meaning it can only get worse as time and miles go by. The filter, if it is doing it's job, will keep particulates under control, because that is all it does. It can not remove acid or other diluted contaminants.

The additive package of the oil has to then handle the rest, which is water (condensation), and products of combustion which forms acids and sludge. Sludge could be retained by the oil filter, and maybe some amount of water.

In the end it is obviously clear by the 15k oil/filter change interval that BMW has extensive faith in their design to warrant this.

The oil analysis I have seen thus far does not confer that one needs to run out and change the lube oil every 5k miles. If it gives you piece of mind, great. I deem it completely unecessary.

Unless you drive in really dirty, dusty conditions, like West Texas or the dessert.

Don't want to start another oil thread...
Today, on my usual way to work, I got low oil warning. Pulled to the parking lot turned of the engine, gave about 5min and checked with the dipstick; the oil shows fine - mid point between max/min. Warning went away after restarting, wonder what's up with that.

Don't want to start another oil thread...
Today, on my usual way to work, I got low oil warning. Pulled to the parking lot turned of the engine, gave about 5min and checked with the dipstick; the oil shows fine - mid point between max/min. Warning went away after restarting, wonder what's up with that.

Sounds like intermittent sensor or wiring harness issue(s). Which is why I personally want to have an oil dipstick - to confirm whether I have a real problem or just a virtual one. I bet you weren't exactly stressed out over the warning once you were able to check the real oil level.

It would seem in this day and age of high tech gadgets, we often get these false warnings, they either reset themselves or when you reset it manually it goes away. You tend to lose confidence in the technology.

I wonder what the pilots of these high tech drive by wire airplanes must go through?

Generally you want to beleive the sensors are right, but when it is intermittent, that can really throw you off.

If I got the low oil alarm and my actual oil was midway between H and L, I think I would be tempted to go ahead and top it off to be on the safe side.

I got my latest analysis... I guess I am not too worried. the numbers are so low that it is probably okay to get an oil change every interval per the computer.

Quote:

Running this oil 11,355 miles may have been just a little too long. Iron accumulated to the point that it may have become abrasive to aluminum and lead, the softer metals in your engine. Aluminum typically comes from pistons and lead shows bearing wear. The good news is that neither metal is so high that your engine will have suffered too much as a result of the excess wear. The oil itself held up nicely. The viscosity is still normal, and the TBN shows active additive left at 1.9. Probably ~10,000 miles will be the optimal oil change for this BMW.

I'm no expert (neither are the "comments writers" at Blackstone), but these UOA's look very good to me. I don't know why exactly but the passenger car diesel UOA's I've seen (here and on the BITOG oil forum) always show relatively high wear metals, particularly when the engines are breaking in. Tighter tolerances? Different metallurgy? And based on what I've seen on the VW TDI diesel forum, the break-in period seems to be rather long - - around 50-60k miles.

If you're UOA-anal, there is a sticky on the VW TDI forum here - http://forums.tdiclub.com/showthread.php?t=154548. About 170 pages of diesel UOA's. Start at the end and work backwards to see the UOA's of diesels (around 2009 and later 2.0 liter TDI's) that are the most similar to our 3.0 six in the BMW.

I'm not trying to start an argument, but I disagree with the oft-stated view that our BMWs are not up to the oil change interval spec'd by the factory. This is the view held by most of the folks on the various forums for gas BMW's where anybody that goes 15-18k miles on a oci is viewed as some sort of cretan whose BMW will surely self-destruct by the time it hits 50-75k mi. Exactly the opposite view is held on the TDI forum where anybody that shortens the 10k mi factory oci on a TDI is viewed as a paranoid idiot. Keep in mind that the sump capacity on the 2.0 liter four cylinder TDI is only four liters of oil. In Europe the factory oci on the same car running the same oil is 18k mi. (30,000 kilometers). I came across a UOA for a euro TDI that was done at 17k mi (27k km) and the car had 120k mi (190k km) on the clock. The lab thought it looked great, too (ppm iron was only around 130+)!

I think our 335d's can do a 10-13k mi oci without even breaking a sweat. Trust in the cbs monitor.

FWIW, I'd recommend not doing an early "break-in" oil change to wash out wear metals, if you haven't already done so. It's no big deal if you have. There's a chance that the factory fill has some special additives - - a break-in oil in other words. The factory fill on our 335d's is a FUCHS oil. FUCHS is known in Europe as the "factory fill specialist" (they were chosen to formulate the oil for the Rolls Royce engines in the Concorde - - one of the most powerful jet engines ever and they only made 63 of them - - that's really being a fill specialist). The tell-tale is the lack of any zinc in the BMW factory fill - - deliberately so as to keep unwanted deposits down. Somehow FUCHS has figured out how to separate the zinc from the active anti-wear agent phosphorous in the zddp. Someone on the TDI forum who visited the VW engine factory in Germany was told that the diesels were filled with a FUCHS oil and was advised not to change the oil before its first scheduled 10k oil change. So, I'd recommend not trying to second-guess BMW's oci's.

Here's a link to a FUCHS oil that is probably pretty close to the factory fill - http://www.thedieselstore.com/templa...VehNum=1117792. It carries the BMW LL04 approval and might be worth a try after the free BMW oil changes run out. It's very clean - - would form very low level of deposits (good for the turbo).

I think our 335d's can do a 10-13k mi oci without even breaking a sweat. Trust in the cbs monitor.....

M6pwr, You say you're not an expert but sounds like you know more than many of us (including the lab rats at Blackstone).

I agree that the BMW OCI is fine for some driving conditions such as for those who drive a lot, and routinely get the engine good and hot to burn off moisture and impurities. But if you are one to drive the car 5 miles each way to work every day and that's about it, the factory recommend OCI will only result in a badly sludged engine.

And while the engine is quite tough and durable, not so sure the turbochargers (bearings) that share that same oil are. So back to my original statement; the extra changes are probably not needed, but on a $50K+ car, it certainly will not hurt, and gives me a little more piece of mind.